ACT scores: Can they predict your success?

ACT scores are good at predicting how well students will do in college. They'd be even better if colleges stopped using the ACT scores for reading and science and focus on math and English scores alone, a study finds.

Michael Dieffenbach sits in his 'classroom' on a typical Monday morning. A senior who attends Wisconsin Virtual Learning school, he just scored a perfect 36 on his ACT test. A recent study finds that ACT scores on math and English are more predictive of college success than scores on reading or science.

It’s that time of year when high school seniors are finding out their ACT scores, test results that could determine where they’ll be accepted into college.

It turns out ACT scores do a pretty good job of predicting how well students will do in school – if you ignore the test’s less relevant parts. Students would save a lot of heartache and schools would avoid a lot of recruitment costs if they used the test scores more intelligently, according to a study released in June.

The trick: Pay attention to the math and English scores and disregard the science and reading sections.

By obscuring the predictive validity of the ACT’s math and English scores, “the Reading and Science tests cause students to be inefficiently matched to schools – admitted to schools that may be too demanding – or too easy – for their levels of ability,” write authors Eric Bettinger and Brent Evans at Stanford University and Devin Pope at the University of Chicago.

For example: If student A gets scores of 26 on reading and science and 22 for math and English, their composite ACT score would be 24, the same as student B who got scores of 22 on reading and science and 26 on math and English. But student A is 59 percent more likely to drop out in the first year of college – and 43 percent more likely in the third year – than student B is.

The effects are large enough to be economically important, the authors find.

Using the ACT math and English scores rather than the composite result to determine college eligibility would help students avoid having to drop out or transfer. Under one scenario, up to 55 percent of students admitted to Ohio schools would move to a more selective or less selective school, according to the study.

For the most selective schools, using the math and science ACT scores would reduce dropout rates by up to 5 to 7 percent, the study finds.

“There are many ways to improve the higher education system, but it often seems that complex problems (such as low college retention rates) require complex solutions,” the authors conclude. “A better understanding of how the ACT predicts future performance could lead to easily implementable, low-cost solutions that can yield potentially large benefits.”